Animal models are essential for understanding the molecular causes for cancers and assessing potential therapeutic approaches. The facility's mission is to maximize the scientific benefits of animal experimentation, while maintaining an emphasis on animal welfare. Both of these efforts have been successful. From the animal welfare standpoint. Animal Resources has been AAALAC accredited since 1988, with the most recent renewal completed in March 2009. Scientifically, the facility has been critical to the success of the Cancer Center, supporting a wide variety of studies, which resulted in over 200 publications in the past funding period. Animal Resources occupies 12,800 sq. ft. of space, almost 10,000 of which belong to the centralized breeding facility, which has been expanded and upgraded to all ventilated caging. For active experimentation, mice are transferred to a facility in the building next door (1,740 sq. ft.). The Resource currently operates at 76% of its current capacity of 9,400 cages, housing more than 480 genetically altered lines of mice. Services include: 1] husbandry 2] breeding colony maintenance (the $0.64/cage per diem rate includes husbandry, breeding, weaning, ear notching, tail sampling) 3] transgenic/knockout mouse facility, 4] in vivo imaging and analysis facility, and 5] technical support (e.g., blood collection, injections, drug administration, tumor measurements, anesthesia, surgeries, post-op care). Operating costs of Resource services are recovered largely on a charge-back basis from facility users, with capital equipment, equipment maintenance, and construction funds provided from Institute support. The current funding period has seen an increase in the use of vivarium resources to study cancer-related phenomena. The Facility offers several standardized models for studying tumor formation and metastasis, and will continue to expand this effort. The In Vivo imaging and Analysis Facility, initiated in the last funding period, supports bioluminescent and fluorescent imaging (Xenogen IVIS200), ultrasound imaging (Visual Sonics Vevo770), along with hematology and serum analysis. The Resource stocks a panel of well characterized standard and luciferase-labeled tumor cell lines, to expand investigators' ability to quantify and characterize tumor progression. Additional imaging instrumentation, such as intravital microscopy and microPET will be evaluated for future acquisition. In 2008, 96% of the Resource users were Cancer Center members, with a total of 40 Cancer Center investigators from all four Programs utilizing the Resource. $124,455 in CCSG support is requested in the first year, representing 4.6% of the total estimated annual operating budget.